Stackable wing for an aerocar

ABSTRACT

A wing includes an upper surface that forms a generally fixed shape and a lower surface adjacent to the upper surface. The lower surface is morphable between a stowed shape and a deployed shape. A method of morphing a wing includes morphing a lower surface between a stowed shape and a deployed shape. The lower surface curves toward the upper surface in the stowed shape and curves away from the upper surface in the deployed shape.

BACKGROUND

The present disclosure pertains to a vehicle that can be flown as afixed wing aircraft and driven as a land vehicle. More specifically, thepresent disclosure is directed to stackable wing architectures therefor.

Flying has always been a dream central to the history of humanity.Aerocars or roadable aircraft are defined as vehicles that may be drivenon roads as well as take off, fly, and land as aircraft. Vehicles thatdemonstrate such capability provide operators with freedom, comfort, andthe ability to arrive quickly to a destination as mobility becomesthree-dimensional yet remains private and personal. Such vehicles,however, may require various trade offs to facilities operations in theflight mode and the roadable mode.

Typically, a body of a land vehicle is relatively short to facilitateparking and road maneuverability, whereas a body of an aircraft isrelatively long to facilitate flight stability and control authority. Inone conventional roadable aircraft, each wing folds upward at a root anddownward a mid-span location to stow against the fuselage in the landmode. Although effective, the more numerous the fold locations, thegreater the weight and complexity that necessarily influencesoperability in each mode. Further, such wing stowage may limit operatoraft and side views conducive to effective operations in the road mode.

SUMMARY

An aerocar including a stackable wing and methods for morphing thestackable wing are disclosed. The wing can include an upper surface ofgenerally fixed shape and a lower surface configured to morph between astowed shape and a deployed shape. The stowed shape is suitable forstacking the wing atop the aerocar in combination with additional wingsin a roadable mode. The deployed shape is suitable for providing lift tothe aerocar in a flight mode.

A wing according to one disclosed non-limiting embodiment of the presentdisclosure includes an upper surface that forms a generally fixed shape;and a lower surface adjacent to the upper surface, the lower surfacemorphable between a stowed shape and a deployed shape.

A wing according to another disclosed non-limiting embodiment of thepresent disclosure includes an upper surface that forms a generallyfixed shape between a leading edge and a trailing edge and a lowersurface between the leading edge and the trailing edge. The lowersurface is morphable between a stowed shape and a deployed shape, thelower surface curves toward the upper surface in the stowed shape, andthe lower surface curves away from the upper surface in the deployedshape.

A method of morphing a wing according to another disclosed non-limitingembodiment of the present disclosure includes morphing a lower surfacebetween a stowed shape and a deployed shape, the lower surface curvingtoward the upper surface in the stowed shape and curving away from theupper surface in the deployed shape.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, the following descriptionand drawings are intended to be exemplary in nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features will become apparent to those skilled in the art fromthe following detailed description of the disclosed non-limitingembodiment. The drawings that accompany the detailed description can bebriefly described as follows:

FIG. 1 is a schematic view of an example aerocar with a stackable wingin a roadable mode retracted toward the body according to one disclosednon-limiting embodiment;

FIG. 2 is a schematic view of the aerocar of FIG. 1 in a first flightmode with all of the stackable wings extended relative to the body;

FIG. 3 is a schematic view of the aerocar of FIG. 1 in a second flightmode with less than all of the stackable wings extended relative to thebody;

FIG. 4 is a schematic view of one stackable wing in the second flightmode of FIG. 3;

FIG. 5 is a schematic sectional view of the wing of FIG. 4 morphed to astowed shape;

FIG. 6 is a schematic sectional view of the wing of FIG. 4 morphed to adeployed shape;

FIG. 7 is a schematic view of an example aerocar with a stackable wingin a roadable mode retracted toward the body according to anotherdisclosed non-limiting embodiment in which each wing is morphablebetween a stowed and a deployed shape;

FIG. 8 is a schematic view of the aerocar of FIG. 7 in a first flightmode with all of the stackable wings extended relative to the body; and

FIG. 9 is a schematic view of the aerocar of FIG. 7 in a second flightmode with less than all the stackable wing extended relative to thebody.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates an aerocar 10 in a roadable mode. Theaerocar 10 generally includes a body 12 with a multiple of wheels 14, ofwhich at least one is a steerable wheel 14A and at least one is a drivewheel 14B, a power system 16, a propulsor system 18 and a stackable wingsystem 20. It should be appreciated that although particular systems andsubsystems are separately defined, each or any of the subsystems may becombined or segregated.

The body 12 provides seating for the operator, passengers and cargo. Thepower system 16 operates to selectively power the drive wheel 14B in theroadable mode as well as the propulsor system 18 such as a pusherpropeller, open rotor, turbofan, or other thrust generation system in aflight mode. It should be appreciated that the roadable mode can includevarious front wheel, rear wheel and all wheel drive configurations. Thepower system 16 may be of various forms to include, but not be limitedto, internal combustion engines, gas turbines, distributed electricpropulsion systems or other energy conversion devices and combinationsthereof.

The stackable wing system 20 selectively extends and retracts withrespect to the body 12 and is that which provides a variable amount oflift for specific flight operations such as takeoff, landing (FIG. 2),and cruise (FIG. 3) operations. It should be appreciated that variousother systems and subsystems such as a deployable empennage withhorizontal and/or vertical stabilizers and various flight controlsurfaces such as a canards, elevators, rudders, ailerons, flaps, slats,flaperons, etc., are contemplated but not shown for the sake of clarityand to focus upon the stackable wing system 20.

The stackable wing system 20 is located generally atop or at leastpartially within the body 12 to maintain the aerocar 10 within containedwidth dimensions to facilitate road operations. That is, each wing 22 ofthe stackable wing system 20 defines a span generally equivalent to awidth of the body 12 to minimize the width of the aerocar 10 when in theroadable mode. The stackable wing system 20 facilitates, for example,parking of the aerocar 10 within typical home garages, parking spots,etc.

Each of the multiple of wings 22 selectively extend individually fromthe body 12 such that the stackable wing system 20 may be tailored forvarious flight operations. For example, all of the multiple of wings 22are closely stacked atop or at least partially within the body 12 forthe roadable mode; all of the multiple of wings 22 are extended from thebody 12 for takeoff and landing operations to provide maximum effectivewing area (FIG. 2); and less than all of the multiple of wings 22 areextended from the body 12 to adjust the effective wing area forefficient cruise operations (FIG. 3). It should be appreciated that theillustrated operational modes are schematic and merely examples in thatvarious other arrangements and intermediate positions will also benefitherefrom. Furthermore, the inter-wing displacement between each of themultiple of wings 22 may alternatively or additionally be individuallyconfigured and controlled to optimize flight operations, stability andmaneuverability.

With reference to FIG. 4, each of the multiple of wings 22 has a leadingedge 30 and a trailing edge 32, the space between which defines thechord. An upper surface 34 and a lower surface 36 that extend betweenthe leading edge 30 and the trailing edge 32 define the desired airfoilshape. The upper surface 34 may also be generally referred to as thesuction side and the lower surface 36 as the pressure side. It should beappreciated that various types of airfoils, e.g., flat bottom,symmetric, non-symmetric, under chamber, and other airfoils may beprovided.

In one disclosed non-limiting embodiment, the upper surface 34 forms arigid shell of a generally fixed shape that may be manufactured of, forexample, a prepreg composite material such as woven fiberglass materialembedded in a suitable resin matrix, a metal alloy such as aluminum, andcombinations thereof. That is, the upper surface 34 is manufactured as agenerally rigid and fixed cross-sectional profile.

The lower surface 36, in contrast to the upper surface 34, is morphable.That is, the lower surface 36 has a variable cross-sectional profilethat can morph between a stowed shape 36A (FIG. 5) and a deployed shape36B (FIG. 6). It should be appreciated that the stowed shape 36A and thedeployed shape 36B may be of various cross-sectional profiles and thecross-sectional profiles depicted are merely schematic.

In this disclosed, non-limiting embodiment, the stowed shape 36Agenerally follows the shape of the upper surface 34 such that themultiple of wings 22 may nest when stowed for the roadable mode (FIG.7). This nestable, stackable wing 22 in this disclosed non-limitingembodiment can thereby morph from the stowed shape 36A (FIG. 5) to thedeployed shape 36B (FIG. 6) as each associated wing 22 is selectivelyextended away from the body 12 to the desired deployed flight mode(FIGS. 8 and 9). That is, the morphable lower surface 36 facilitates acompact, closely stowable architecture with respect to the vehicle body12 but morphs to the deployed shape 36B (FIG. 6) for the flight mode.Such a closely stowable architecture facilitates, for example, a lowprofile and stylish body design potential when in the roadable mode thatalso does not interfere with the side and aft view for the driver.

In this disclosed, non-limiting embodiment, the deployed shape 36B ofthe lower surface 36 extends generally away from the upper surface 34 toform the airfoil shape. In other words, the stowed shape 36A forms acompact shape of reduced thickness while the deployed shape 36B formsthe airfoil shape. That is, the lower surface 36 curves toward the uppersurface 34 in the stowed shape 36A and the lower surface 36 curves awayfrom the upper surface 34 in the deployed shape 36B.

The lower surface 36 may be manufactured of a bistable morphing materialsuch as a bistable composite operable to snap from one stable shape intoanother, e.g., between the stowed shape 36A (FIG. 5) and the deployedshape 36B (FIG. 6). Bistable composites are a type of compositestructure that have two statically stable modes. This bi-stabilityproperty results from locked, in-plane residual stresses and may beparticularly appropriate to an adaptive structure such as the lowersurface 36 as continued power is not required to hold each stable mode.The change between stable states is physically realized as a jumpphenomenon or snap-through, which is strongly non-linear in nature.

Bistable composites may include non-symmetric laminates, where there aremultiple fiber directions within the lay-up such that a bistable curveis formed. Further, various thicknesses may also be provided in thelay-up of the lower surface 36 to control the shape of the curve andthus produce a desired airfoil profile. It should be appreciated thatalthough a bistable morphing material is disclosed in the illustratedembodiment, tri-stable as well as other adaptive structures will benefitherefrom.

With continued references to FIG. 4-6, the lower surface 36 may beselectively morphed between the stowed shape 36A and the deployed shape36B by an actuator 40. The actuator 40 may, for example, include anelectrical power source that applies an electric current to generateJoule heating within an electric heating material embedded within themorphing bi-stable laminate. The embedded electric heating material isoperable to selectively elevate the temperature to effect movementbetween states. This morphing bi-stable laminate can thereby morph fromone stable state to the other stable state by the heating effect.

In another example, the actuator 40 may be an air source that isoperable to apply a pressure to “snap” the lower surface 36 to thedeployed shape 36B or a suction to “snap” the lower surface 36 to thestowed shape 36A. It should be appreciated that various other actuatorswill benefit herefrom.

The actuator 40 may be operated in response to a control subsystem 42that generally includes a control module 44 with a processor 46, amemory 48, and an interface 50. The processor 46 may be any type ofmicroprocessor having desired performance characteristics. The memory 48may include any type of computer readable medium which stores the dataand control algorithms described herein such as those that deploy andconfigure the wings 22 for the desired flight operations.

With reference to FIGS. 5 and 6, to facilitate maintaining the lowersurface 36 in the deployed shape 36B, one or more articulable spars 60extends between the lower surface 36 and the upper surface 34. Thearticulable spars 60 function as structural members within each wing 22to react to the torsional, bending, shear, and other loads developedwithin the wing 22 during flight operations. As defined herein“articulable” includes but is not limited to folding, telescoping,bending, hinging, and other movement. In one disclosed non-limitingembodiment, bistable material may be utilized to facilitate movement andstable positions of the articulable spars 60 in both the stowed shape36A and the deployed shape 36B.

It should be understood that relative positional terms such as“forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like arewith reference to the normal operational attitude of the vehicle andshould not be considered otherwise limiting.

Although the different non-limiting embodiments have specificillustrated components, the embodiments of this invention are notlimited to those particular combinations. It is possible to use some ofthe components or features from any of the non-limiting embodiments incombination with features or components from any of the othernon-limiting embodiments.

It should be understood that like reference numerals identifycorresponding or similar elements throughout the several drawings. Itshould also be understood that although a particular componentarrangement is disclosed in the illustrated embodiment, otherarrangements will benefit herefrom.

Although particular step sequences are shown, described, and claimed, itshould be understood that steps may be performed in any order, separatedor combined unless otherwise indicated and will still benefit from thepresent disclosure.

The foregoing description is exemplary rather than defined by thelimitations within. Various non-limiting embodiments are disclosedherein, however, one of ordinary skill in the art would recognize thatvarious modifications and variations in light of the above teachingswill fall within the scope of the appended claims. It is therefore to beunderstood that within the scope of the appended claims, the disclosuremay be practiced other than as specifically described. For that reasonthe appended claims should be studied to determine true scope andcontent.

What is claimed is:
 1. A wing comprising: an upper surface that forms agenerally fixed shape; and a lower surface adjacent to said uppersurface, wherein said lower surface is morphable between a stowed shapeand a deployed shape, wherein said wing has a compact cross-sectionalprofile of reduced thickness when said lower surface has said stowedshape, wherein said wing has an airfoil shape when said lower surfacehas said deployed shape, wherein said wing is one of a multiple of wingsnested atop a body of an aerocar in a roadable mode and selectivelyextendable in a substantially vertical direction with respect to saidbody in a flight mode, wherein said wing has said compactcross-sectional profile in said roadable mode, and wherein said wing hassaid deployed shape in said flight mode.
 2. The wing as recited in claim1, wherein said lower surface extends between a leading edge and atrailing edge of said upper surface.
 3. The wing as recited in claim 1,wherein said lower surface comprises a morphable material.
 4. The wingas recited in claim 1, wherein said lower surface comprises a bistablecomposite.
 5. The wing as recited in claim 1, wherein said stowed shapelocates said lower surface adjacent to and generally following a contourof said upper surface.
 6. The wing as recited in claim 1, wherein saiddeployed shape displaces said lower surface to be spaced from said uppersurface.
 7. The wing as recited in claim 1, wherein said lower surfacecurves toward said upper surface in said stowed shape.
 8. The wing asrecited in claim 1, wherein said lower surface curves away from saidupper surface in said deployed shape.
 9. The wing as recited in claim 1,wherein said upper surface is comprises a composite material.
 10. Thewing as recited in claim 1, wherein said upper surface comprises a metalalloy material.
 11. The wing as recited in claim 1, further comprisingan articulable spar extending between said lower surface and said uppersurface, said articulable spar having a collapsed configurationsupporting said lower surface in said stowed shape an extendedconfiguration supporting said lower surface in said deployed shape. 12.A wing comprising: an upper surface that forms a generally fixed shapebetween a leading edge and a trailing edge; and a lower surfaceextending between said leading edge and said trailing edge, wherein saidlower surface is morphable between a stowed shape and a deployed shape,wherein said lower surface is adjacent to and follows a contour of saidupper surface in said stowed shape, wherein said lower surface is spacedfrom and curves away from said upper surface in said deployed shape,wherein a pressure is selectively applied between said upper surface andsaid lower surface to morph said lower surface between said stowed shapeand said deployed shape, and wherein said wing is one of a multiple ofwings nested atop a body of an aerocar in a roadable mode andselectively extendable in a substantially vertical direction withrespect to said body in a flight mode.
 13. The wing as recited in claim12, wherein said lower surface is manufactured of comprises a bistablecomposite.
 14. The wing as recited in claim 12, further comprising anarticulable spar extending between said lower surface and said uppersurface, said articulable spar having a collapsed configurationsupporting said lower surface in said stowed shape and an extendedconfiguration supporting said lower surface in said deployed shape. 15.The wing as recited in claim 12, further comprising an actuatorconfigured to apply said pressure to said lower surface to morph saidlower surface between said stowed shape and said deployed shape.
 16. Amethod of morphing a wing, the wing including an upper surface and alower surface, the lower surface being morphable between a stowed shapeand a deployed shape, the method comprising: morphing the lower surfaceof the wing between the stowed shape and the deployed shape, wherein thelower surface curves toward the upper surface of the wing in the stowedshape and curves away from the upper surface in the deployed shape, andwherein morphing includes selectively heating a bistable compositewithin the lower surface to elevate a temperature of the bistablecomposite and effect movement of the lower surface between the stowedshape and the deployed shape, the upper surface of the wing forming agenerally fixed shape, the lower surface of the wing being adjacent tothe upper surface, the wing having a compact cross-sectional profile ofreduced thickness when the lower surface has the stowed shape, the winghaving an airfoil shape when the lower surface has the deployed shape,the wing being one of a multiple of wings nested atop a body of anaerocar in a roadable mode and selectively extendable in a substantiallyvertical direction with respect to the body in a flight mode, the winghaving the compact cross-sectional profile in the roadable mode, and thewing having the deployed shape in the flight mode.